The objective of the Transgenic Mouse/ES Cell Shared Resource to investigators production is assist in the and use of transgenic and gene knockout mice. Through an interdisciplinary approach, the Resource has been able to provide a broader array of services than are available elsewhere to a large base of investigators. The Shared Resource focuses on quality control, the increased potential for collegial interactions, and immediate access to individuals with deep knowledge of transgenic mice. Experienced personnel develop new procedures and applications, such as those that facilitate the use of site-specific recombinases to perform tissue-specific gene knockouts. As the technology for genome manipulation continues to expand, the Transgenic Mice/ES Cell Shared Resource is likely to grow with it. Specifically, the Shared Resource offers pronuclear DNA microinjection; ES cell microinjection into blastocysts; assisted reproduction; gene targeting; and conditional knockouts utilizing the Cre or FIp(e) site-specific recombinase system; embryo cryopreservation and long-term storage; and sperm cryopreservation and storage. Dr. Cathleen Pettepher is the Director of the Transgenic Mouse/ES Cell Shared Resource and offers consultation to investigators, reviews and approves requests for gene targeting experiments and DNA or ES cell microinjections, and tracks the efficiency and quality of the services offered. She has a highly-trained staff that helps her serve VICC researchers.